i see this happen many times for many years. i don't like it but it never
seem to do anything bad so i just say that how excel is sometime whn you use
screenupdating = false.


"Joe User" <joeu2004 wrote in message
...
|I am using WinXP SP3 and Excel 2003 SP3 with VBA 6.5.
|
|
| I have a long-running macro that is CPU-intensive. However, about every 1
| sec, I log some information and sleep for 20 msec.
|
| After "a while" (it varies), one or more open windows go blank. That is,
| there is nothing but white inside the window frame. Moreover, my VBA
window
| is no longer the active window -- none is.
|
| When I log to the Immediate Window, that window goes blank very soon,
often
| as soon as one page is filled (i.e. the window scrolls).
|
| But this also happens when I log to a file -- and this time, it happened
to
| all windows, foreground and background. (I had walked away from the
| computer for about 45 min.)
|
| The system is still responsive. When I "break" and end the macro,
| everything is usually restored to normal. But it is still disconcerting.
|
| Any idea why that happens? Any idea how I can avoid it?
|
| I suspect this is really a WinXP issue. Any idea what NG would be
monitored
| by responsive people who are knowledgable in this area (the O/S)?
|
| I've tried posting such technical questions to m.p.windowsxp.general in
the
| past. The response are usually not impressive.
|
| I have extensive O/S background, albeit not with MS Windows. 20 msec is
| usually at least two "ticks" (about 33 msec on WinXP). That is usually
| plenty of time to run other non-CPU-intensive processes, e.g. for window
| updates and timer-based bookkeeping.
|
| Nonetheless, in other circumstances, I have extended the sleep to as much
as
| 1 sec, to no avail.
|